The invention relates generally to a vending machine for dispensing products, and more specifically relates to a control means for a coin operated vending machine having a plurality of product selections.
In many prior control systems for vending machines, a credit signal is generated after the proper coins have been accepted by the vending machine. Upon activating a product selection switch when the credit signal is present, a product release means such as a solenoid means or a motor means, caused the product to be released.
In the prior electromechanical vending control systems, as for example of the relay version, finite delay periods, such as the relay drop out time, were inherent in these systems. Thus, the possibility of beating or cheating the system nearly always existed. Many of the more recent vending machine controls comprised solid state circuitry which on the most part, eliminated the undesirable long delay periods. In a previous solid state system, a a credit-thyristor switch was used to switch from one state to another state, in response to the credit signal, (after the proper coins were accepted by the machine) to cause charging of a trigger capacitor. When a product selection was made, the voltage from the trigger capacitor was coupled via the product selection switch to the gate of an activator-thyristor switch, to fire "on" the thyristor, thereby providing a discharge path for a storage capacitor through the corresponding product release solenoid and the activator-thyristor. The product was released the solenoid was de-energized, and the thyristor switches were switched back to their normal positions, after the storage capacitor had discharged. Although the afore-described solid state system was operable, its complexity and cost precluded any extensive commercial use thereof. The subject invention on the ohter hand, improves thereover by greatly simplifying the solid state circuitry and the cooperative parts between such circuits and the electromechanical elements of the vending machine.